Thermal management of electronic cabinets traditionally was achieved by air flow in the A/C controlled environment. Recently, many customers started to apply fresh air cooling systems with no control over temperature and humidity. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) recommends for IT data centers allowable temperature/humidity envelope in the range of 15 to 32° C. (59-90° F.) and 20-80% RH respectively. As a result of free air cooling application, ASHRAE points two primary objectives for data centers: reliability and energy efficiency. Because some geographic areas are characterized by relatively high temperature and humidity of air, it can significantly reduce service life of data systems due to thermal derating and corrosion due to presents of chemically active contaminants in humid air.
Many computer and telecommunication rooms rely on forced air convection to cool the electronic Information Technology (IT) equipment. The power density of the IT equipment has continued to increase, thus requiring more air to cool the equipment. The quality of the air often is not monitored and certain combinations of chemical species along with higher temperature and humidity can accelerate metal corrosion. Certain geographic areas around the world have high concentrations of oxidizers (NO2, O3), sulfur dioxide and other impurities in the air. The increased use of “free cooling” brings outside air directly into the data center, which could be high in impurities and accelerate corrosion rates with the electronic equipment.
Most of the electronic IT equipment available today is designed to be lower cost and made on high volume, robotic assembly lines. The smaller components and increased pitch along with less protective solder mask and cheaper materials exacerbate the formation of creep corrosion. The corrosion can “bloom” and spread to adjacent pin signals and short circuit them. This can lead to hardware failures and potential “data unavailable” (DU), and in some instances “data loss” (DL) errors. To ensure fault tolerance, and serviceability levels, redundant equipment is often required, increasing costs and energy use. The higher failure rate, also leads to increased customer service replacement cost and maintenance.